Some people put a great deal of value in grammar during acquisition of a second language. Others don’t. Personally, I fall in with the latter group, due primarily to my own experiences in language learning.
While I do believe that learning grammar has its place, it’s probably better reserved for more advanced learners. Those on the beginner and intermediate levels are usually best served using other strategies — they need to instinctively form the connections first before being treated to the technical details of language use.
Feedback is great for language learners. When that feedback takes the form of grammar corrections, however, the input merely becomes an attempt to treat a surface issue in your usage of the language — one that isn’t likely to work since language skills always seem to develop in a more complex and gradual process.
Learning of linguistic items, especially grammatical structures, also tend to occur in non-linear fashion, making it hard to tie into a student’s level of development. Correcting someone’s grammar doesn’t necessarily mean they’ll be able to grasp the underlying reasons for the suggestions. As a result, the feedback tends to fall on deaf (or, rather, unprepared) ears.
Here’s the confusing part. I’ve seen some grammar-based language software that I’ve recommended friends avoid. Yet, when some of them used those resources, they appeared to learn at a pace comparable to learners using a totally different strategy. My point? Don’t take what any expert says at face value — find out for yourself whether a particular language education software can truly be helpful for you.